1. Field of the Invention
This invention relates to an encapsulation apparatus for producing capsules by coagulating liquid or sol foods such as dressings, alcoholic drinks, or fruit juice (hereinafter generically referred to as "dressings").
2. Description of the Conventional Art
Since dressings are generally in the state of liquid or sol, there are a variety of limitations in using or taking the dressings. However, the dressings have not always to be used in the form of liquid or sol, but they just have been used in such a traditional or customary manner. Thus, the dressings have become to be processed by solidifying into granular or spherical shapes of an adequate size to expand the use of the dressings. To solidify the dressings, there has been generally known a method which uses a cross-linking reaction to form a film on the surface of the dressings. In the method, a calcium salt is added to the dressings to obtain a material solution which is added dropwise into a coagulating solution consisting mainly of a polysaccharide such as alginic acid or pectin to form a film of calcium alginate or the like on the surface of the material solution. The resulting product includes the uncoagulated material solution encapsulated inside the coagulated film. The encapsulated product is hereinafter referred to as "capsules". Since the thus obtained capsules have different compositions of the inside material and the film, they have a feature that when the film is broken by teeth, as for the case of citrus fruits, for example, the flavor of the contents spreads in the mouth. However, this method has a problem that since the capsules during the chemical reaction between the material solution drops and the coagulating solution still have a stickiness, the capsules may adhere to each other to agglomerate into lumps. For example, Japanese Patent Publication No. 31183/1983 describes an apparatus for continuously producing capsules. It was noted that in this apparatus the capsules impinge against each other to agglomerate in the coagulating solution during the coagulation process. In the apparatus, as shown in FIG. 7, a material solution is added dropwise from a pressurized dropping tank 5 to a coagulation tank 6 to coagulate into capsules. The coagulation tank 6 is a hopper-shaped deep vessel which is provided with an electric fan disposed on the bottom surface to stir the capsules. The capsules, after staying for an adequate period of time in the coagulation tank 6, flow into a film formation tank 7 where the capsules stay for an adequate period of time. The film formation tank 7 is provided on its bottom surface with an electric fan to stir the capsules. The capsules discharged from the film formation tank 7 are separated from the coagulating solution by means of a conveyor 8 and then fed into a subsequent process. Thus, because the material solution is added dropwise into the deep coagulation tank 5, and the capsules during the coagulation process are agitated by the electric fan, the capsules are liable to adhere to each other to form lumps. To eliminate such a problem, the dropping rate of the material solution per unit of time can be reduced, however, this results in a deterioration of productivity. Further, because the time of staying in the coagulation tank 5 differs between individual capsules (ranging from about 10 to 60 seconds), there results a mixture of overreacted capsules and unreacted capsules. Moreover, this apparatus requires conveyors 8 and 9, the electric fan, and a pressure controlling device, resulting in an increased manufacturing cost.
With a view to obviate all of the conventional art defects of encapsulation apparatus, it is a primary object of the present invention to provide a low-cost encapsulation apparatus which can produce capsules with enhanced efficiency, without agglomeration of the capsules.